1. Technical Field
Exemplary embodiments of the present disclosure are directed to a light guide plate and a light-emitting assembly having the light guide plate. More particularly, exemplary embodiments of the present disclosure are directed to a light guide plate used for a liquid crystal display (LCD) apparatus and a light-emitting assembly having the light guide plate.
2. Description of the Related Art
In general, a light-emitting assembly providing light to an LCD panel may be classified as either an edge-illumination type or a direct-illumination type according to a position of a light source unit generating the light. In an edge-illumination type, the light-emitting assembly includes a light guide plate for efficiently guiding the light received from the light source unit to the LCD panel. The light guide plate includes a diffusion pattern to change the light path. The diffusion pattern can uniformly provide an incident light propagating through a light incident surface of the light guide plate to a light exiting surface of the light guide plate. The diffusion pattern is formed on a surface facing the light exiting surface. The diffusion pattern includes a plurality of particles for diffusing the light. Due to the optical properties of the particles, the light provided to the opposite surface may be uniformly emitted from the light exiting surface.
When a refractive index of the diffusion particles is large, light may be easily diffused by the diffusion particles, enhancing the light-diffusion properties of the particles. However, a highly diffusive particle having relatively large refractive index, such as titanium dioxide (TiO2), has a high light absorption in a blue wavelength range when compared to normally diffusive particles. Thus, when a proportion of a highly diffusive particle such as titanium dioxide is increased in the diffusion pattern, brightness and brightness uniformity may be enhanced. However, a color difference may be generated due to the increase of the amount of the titanium dioxide. This color difference may be resolved by newly-developed highly diffusive particles having a relatively large refractive index with a low light absorption in the blue wavelength range. However, these highly diffusive particles are challenging to develop due to high cost and increased manufacturing time, decreasing manufacturing productivity of the light guide plate.
The thickness of the light-emitting assembly may be decreased by decreasing the size of the light source unit, reducing the number of optical sheets (or plates), or decreasing the thickness of the optical sheets (or plates). For example, the thickness of the light guide plate, which is a main contributor to the thickness of the edge-illumination type light-emitting assembly, may be decreased, and light emitting diodes (LEDs) may be used as the light source unit, to decrease a thickness of an LCD apparatus using the light-emitting assembly. However, decreasing the thickness of the light guide plate changes the light path resulting in more blue light being absorbed by the highly diffusive particles, such as titanium dioxide, increasing color differences and decreasing display quality.